Sensor assembly, system including RFID sensor assemblies, and method

ABSTRACT

A system comprises a valve; a plurality of RFID sensor assemblies coupled to the valve to monitor a plurality of parameters associated with the valve; a control tag configured to wirelessly communicate with the respective tags that are coupled to the valve, the control tag being further configured to communicate with an RF reader; and an RF reader configured to selectively communicate with the control tag, the reader including an RF receiver. Other systems and methods are also provided.

GOVERNMENT RIGHTS

This invention was made with government support under contract numberDE-AC0676RL01830 awarded by the U.S. Department of Energy. TheGovernment has certain rights in the invention.

TECHNICAL FIELD

The invention relates to sensors. The invention also relates to valvesand process control.

BACKGROUND OF THE INVENTION

Industrial process control environments typically require physicalsensing of parameters such as temperature, pressure, flow rate, strain,displacement, humidity, vibration, etc. Adapting a sensor network andits cabling infrastructure to existing plant environments is usuallycost prohibitive.

Various sensors that incorporate transmitters are known in the art. Forexample, U.S. Pat. No. 5,774,048 (incorporated herein by reference)relates to a valve that generates a wireless transmittable signal ifpressure drops within vehicle tires. U.S. Pat. No. 6,005,480 to Banzhofet al. relates to similar subject matter.

U.S. Pat. No. 6,199,575 to Widner (incorporated herein by reference)discloses a valve system that includes a MEMS pressure sensor thatsenses pressure and functions as a mechanical actuator for a valve. Atransmitter is integrated with the valve and a receiver is located at aremote location. A transmitter may be formed on the MEMS along with apressure transducer and its associated circuitry. An alternativeembodiment is disclosed in which a digital modulator is included in atransducer valve.

U.S. Pat. No. 6,445,969 to Kenney et al. (incorporated herein byreference) discloses a system and method of monitoring processparameters associated with a manufacturing or testing process. Thisreference discloses that radio frequency identification tags may be usedto transmit an event signal. If an event trigger is detected, a commandis sent to a particular sensor to measure a specified process parameter.

U.S. Pat. No. 6,484,080 to Breed discloses an acceleration sensorincluding an RFID unit. U.S. Pat. No. 6,563,417 to Shaw discloses anRFID tag including a temperature sensor.

Pneumatic or fluid controlled valves are known in the art and used in avariety of applications, such as to control water and other fluids innuclear reactors. Such valves are discussed in U.S. Pat. No. 5,197,328to Fitzgerald; U.S. Pat. No. 6,026,352 to Burns et al.; U.S. Pat. No.5,329,956 to Marriott et al.; and U.S. Pat. No. 5,774,048 to Achterholt,all of which are incorporated by reference. In a typical pneumaticoperated valve, a current to pressure (I/P) transducer is coupled to avalve positioner which supplies an operating pneumatic pressure to avalve diaphragm actuator. The diaphragm actuator in turn is coupled to asliding valve stem and plug. Feedback is provided by a mechanicallinkage, such as by a valve positioner arm having one end connected tothe actuator/valve stem and the other end coupled to the positioner soas to track movement of the valve stem. Alternatively, electrical signalfeedback is provided from installed valve positioner instrumentation.

The value of sensor for providing both diagnostics and prognostics isreadily accepted; however, innovative technical developments are neededto facilitate the implementation.

SUMMARY OF THE INVENTION

Some aspects of the invention provide a system comprising a valve; aplurality of RFID sensor assemblies coupled to the valve to monitor aplurality of parameters associated with the valve; a control tagconfigured to wirelessly communicate with the respective tags that arecoupled to the valve, the control tag being further configured tocommunicate with an RF reader; and an RF reader configured toselectively communicate with the control tag, the reader including an RFreceiver:

Other aspects of the invention provide a suite of RFID sensor assembliesfor use in industrial process control. The suite can include, forexample, sensors configured to sense one or more of temperature,pressure, strain, or other process control parameters. In some aspectsof the invention, a tailored mechanical package is provided to allow theRFID tag to be readily adapted to a particular process component orparameter.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a block diagram of a system including a pneumatically operatedvalve and a plurality of RFID sensor assemblies embodying variousaspects of the invention.

FIG. 2A is a circuit schematic of a RFID sensor assembly.

FIG. 2B is a reader embodying various aspects of the invention.

FIG. 3 is a perspective view of an RFID sensor assembly in accordancewith some embodiments.

FIG. 4 is a perspective view of an RFID sensor assembly in accordancewith other embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a system embodying various aspects of the invention. Thesystem 9 includes a fluid control or pneumatically operated valve 10.The air operated valve 10 includes a control valve 11, a pneumaticdiaphragm actuator 12, a stem coupler 13, a valve positioner 14, apressure or volume booster 15, a controller and I/P or E/P converter 16,a sensor 17, an air regulator 18, and a pneumatic fluid supply line 19.The valve 11 controls fluid flow through a main fluid line 20. The mainfluid line 20 transfers fluid in connection with an industrial process.For example, the main fluid line could transfer fluid used in a powerplant (e.g., water or other fluids used in a nuclear power plant). Thefluid line 20 may be any other sort of fluid line in an industrialprocess facility.

In the illustrated embodiment, a condition of the fluid line 20 issensed (e.g., temperature, pressure, flow) and this information is sentto the valve positioner 14. For example, in the illustrated embodiment,the sensor 17 is a pressure transducer that senses pressure upstream ofthe valve 11. In alternative embodiments, different parameters can besensed either upstream or downstream of the valve 11. In the illustratedembodiment, an electro-pneumatic type valve positioner 47 is shown,including pneumatic positioner 14 and I/P converter 16. The sensor 17provides an output, which is an electrical output in the illustratedembodiment. More particularly, in the illustrated embodiment, the sensor17 provides a current output. The converter 16 is coupled to the sensor(transducer) 17 and converts an electrical signal (current in theillustrated embodiment) from the sensor 17 to pressure. Other I/P or E/Pconverters could be employed. In some embodiments, the sensor 17provides a signal that can be directly used by the valve positioner 14and the converter 16 is omitted. In alternative embodiments, converter16 can receive electrical signals from the valve position controller 39,from the sensor 17, or from both the valve position controller 39 andthe process sensor 17. The valve position controller 39 is a remotecontroller, in some embodiments. The valve position controller 39 is amanually operable controller in some embodiments.

In the illustrated embodiment, the converter 16 is coupled to the valvepositioner 14 which supplies an operating pneumatic pressure to theactuator 12. The diaphragm actuator 12 includes a diaphragm 21, and aspring 23 operating on the diaphragm. The diaphragm actuator 12 can beof a type that is opened by pneumatic fluid and closed by the spring, orcan be of a type that is closed by a pneumatic fluid and opened by thespring. The actuator 12 is coupled to a sliding valve stem 24 and to thecontrol valve 11. The spring 23 is biased between the valve stem 24 andthe diaphragm 21. Feedback is provided by the actuator-valve stemcoupler 13 which has one end connected to the valve stem 24 and anotherend coupled to the positioner 14 so as to track movement of the valvestem 24. As the valve 11 approaches the closed position, feedback isused to seat the valve 11 without slamming. The regulator valve 18merely reduces pressure from pneumatic supply line 19 and booster 15merely increases pressure to a level required to operate the pneumaticactuator 12.

Alternative arrangements are possible. For example, while the pneumaticactuator 12 shown in FIG. 1 is a direct-acting pneumatically operateddiaphragm actuation, in which increasing pneumatic pressure pushes downon the diaphragm 21 extending the actuator stem 24, alternative actuatortypes could be employed. For example, in one alternative embodiment (notshown), a reverse-acting pneumatically operated diaphragm actuator typeis employed in which increasing pneumatic pressure pushes up on thediaphragm and retracts the actuator stem. In another alternativeembodiment (not shown), a reversible type pneumatic actuator is employedthat can be assembled and installed as either a direct-acting orreverse-acting type pneumatic actuator.

Similarly, while an electro-pneumatic type valve positioner 47 is shownin FIG. 1, including pneumatic positioner 14 and I/P converter 16,alternative embodiments are possible. For example, while an analog typeelectro-pneumatic positioner 14 is shown in FIG. 1, a digitalelectro-pneumatic positioner is used in alternative embodiments.Further, in some applications a pneumatic type positioner will be used.In these embodiments, the pneumatic positioner 14 receives a pressureinput signal directly from the process sensor 17 or valve positioncontroller 166.

In some embodiments, a plurality of RFID sensor assemblies is providedto establish on-line self-diagnostic, prognostic, and calibrationcapabilities for the pneumatically operated valve. To instrument acomponent such as the pneumatically operated valve 10, individual RFIDsensor assemblies are attached to monitor various parameters. VariousRFID sensor assemblies may have unique sensor interfaces. Moreparticularly, the RFID sensor assemblies include mounting structure suchthat the mounting and sensing is noninvasive to normal valve operation.Some such mounting structures are described below in connection withFIGS. 3 and 4.

The RFID sensor assemblies are used, in the embodiment of FIG. 1, toprovide on-line or in-use self-diagnostic, prognostic, and calibrationcapabilities for pneumatically operated process control valves andcontrol system components. For example, RFID sensor assemblies can becoupled to or proximate (e.g., upstream or downstream of) componentssuch as, for example, the I/P or E/P converter 16, the valve positioner14, the pressure or volume booster 15, the actuator spring 23, thepacking of the control valve 11, and the fluid supply regulator valve18. In FIG. 1, an RFID sensor assembly 31 is coupled to an electricalconductor 41 between the converter 16 and the valve positioner 14, anRFID sensor assembly 32 is coupled to the actuator-valve stem coupler13, an RFID sensor assembly 33 is coupled to a conduit 22 between thebooster 15 and the pneumatic actuator 21, an RFID sensor assembly 34 iscoupled to a conduit 43 between the valve positioner 14 and the booster15, an RFID sensor assembly 35 is coupled to a conduit 45 between thevalve positioner 14 and regulator valve 18, an RFID sensor assembly 36is coupled to pneumatic supply line 19 between feeds to the regulatorvalve 18 and to the booster 15, and RFID sensor assemblies 37 arecoupled to the process line or conduit 20 on either side of the controlvalve 11.

The use of RFID sensor assemblies 31-37 allows for condition monitoring(e.g., periodic monitoring and data logging) of important valveperformance parameters such as valve seating force, spring 23 preloadand spring constant, bench set, spring packing drag or bearing frictionloads, linearity of the spring 23, condition of the diaphragm 21, andvalve 11 position, stroke times, and calibration. Bench set comprisescompression on the spring.

In the illustrated embodiment, the system 9 further includes an RFIDcontrol tag 38, and each of the RFID sensor assemblies 31-37communicates to the control tag 38. This is, in some embodiments, abi-directional link so that the control tag 38 can request data from theRFID sensor assemblies 31-37 and also communicate with a reader. Thesystem 9 further includes a reader 40 defined by, for example, aportable computer 42 such as a laptop or personal digital assistant plusan RF receiver or module 44 coupled to the laptop or personal digitalassistant for communication with the laptop or personal digitalassistant. Communication can be via an RS-232 link, PCMCIA connection,serial port, or other communication link. In the illustrated embodiment,the computer 42 includes software that allows for data transfer from thecontrol tag 38 and/or the RFID sensor assemblies 31-37. The software (orseparate software) permits setting up the tags.

In other embodiments, the RFID sensor assemblies 31-37 communicatedirectly with the reader, instead of through the control tag 38.

In the illustrated embodiment, the RF link between the reader 40 and thecontrol tag 38 (and/or the sensor assemblies 31-37) is a low power link.For example, low power is used for transmissions. This allows theread/write range to be restricted to a predetermined range. Therestricted read/write range allows for multiple networks to be placed inzones or grids, much like cell phone grids, without crossover RFinterference.

The tags have individual IDs, only tags with requested IDs will respond.In the illustrated embodiment, the tags and reader operate in afrequency band that does not require government licensing such as theISM (industrial scientific measurement) band in the U.S. or frequencybands that similarly do not require government licensing in othercountries.

The RFID sensor assemblies 31-37 could be or include, in someembodiments, RFID tags that are the same as or substantially similar tothe RFID tags described in the following patent applications, which areincorporated herein by reference: U.S. patent application Attorney Ser.No. 10/263,826, filed Oct. 2, 2002, entitled “Radio FrequencyIdentification Device Communications Systems, Wireless CommunicationDevices, Wireless Communication Systems, Backscatter CommunicationMethods, Radio Frequency Identification Device Communication Methods anda Radio Frequency Identification Device” by inventors Michael A. Hughesand Richard M. Pratt; U.S. patent application Ser. No. 10/263,809, filedOct. 2, 2002, entitled “Method of Simultaneously Reading Multiple RadioFrequency Tags, RF Tag, and RF Reader”, by inventors Emre Ertin, RichardM. Pratt, Michael A. Hughes, Kevin L. Priddy, and Wayne M. Lechelt; U.S.patent application Ser. No. 10/263,873, filed Oct. 2, 2002, entitled“RFID System and Method Including Tag ID Compression”, by inventorsMichael A. Hughes and Richard M. Pratt; U.S. patent application Ser. No.10/264,078, filed Oct. 2, 2002, entitled “System and Method to IdentifyMultiple RFID Tags”, by inventors Michael A. Hughes and Richard M.Pratt; U.S. patent application Ser. No. 10/263,940, filed Oct. 2, 2002,entitled “Radio Frequency Identification Devices, BackscatterCommunication Device Wake-Up Methods, Communication Device Wake-UpMethods and A Radio Frequency Identification Device Wake-Up Method”, byinventors Richard Pratt and Michael Hughes; U.S. patent application Ser.No. 10/263,997, filed Oct. 2, 2002, entitled “Wireless CommunicationSystems, Radio Frequency Identification Devices, Methods of Enhancing aCommunications Range of a Radio Frequency Identification Device, andWireless Communication Methods”, by inventors Richard Pratt and StevenB. Thompson; U.S. patent application Ser. No. 10/263,670, filed Oct. 2,2002, entitled “Wireless Communications Devices, Methods of Processing aWireless Communication Signal, Wireless Communication SynchronizationMethods and a Radio Frequency Identification Device CommunicationMethod”, by inventors Richard M. Pratt and Steven B. Thompson; U.S.patent application Ser. No. 10/263,656, filed Oct. 2, 2002, entitled“Wireless Communications Systems, Radio Frequency IdentificationDevices, Wireless Communications Methods, and Radio FrequencyIdentification Device Communications Methods”, by inventors RichardPratt and Steven B. Thompson; U.S. patent application Ser. No.10/263,635, filed Oct. 4, 2002, entitled “A Challenged-Based TagAuthentication Model”, by inventors Michael A. Hughes and Richard M.Pratt; U.S. patent application Ser. No. 09/589,001, filed Jun. 6, 2000,entitled “Remote Communication System and Method”, by inventors R. W.Gilbert, G. A. Anderson, K. D. Steele, and C. L. Carrender; U.S. patentapplication Ser. No. 09/802,408; filed Mar. 9, 2001, entitled“Multi-Level RF Identification System”; by inventors R. W. Gilbert, G.A. Anderson, and K. D. Steele; U.S. patent application Ser. No.09/833,465, filed Apr. 11, 2001, entitled “System and Method forControlling Remote Device”, by inventors C. L. Carrender, R. W. Gilbert,J. W. Scott, and D. Clark; U.S. patent application Ser. No. 09/588,997,filed Jun. 6, 2000, entitled “Phase Modulation in RF Tag”, by inventorsR. W. Gilbert and C. L. Carrender; U.S. patent application Ser. No.09/589,000, filed Jun. 6, 2000; entitled “Multi-Frequency CommunicationSystem and Method”, by inventors R. W. Gilbert and C. L. Carrender; U.S.patent application Ser. No. 09/588,998; filed Jun. 6, 2000, entitled“Distance/Ranging by Determination of RF Phase Delta”, by inventor C. L.Carrender; U.S. patent application Ser. No. 09/797,539, filed Feb. 28,2001, entitled “Antenna Matching Circuit”, by inventor C. L. Carrender;U.S. patent application Ser. No. 09/833,391, filed Apr. 11, 2001,entitled “Frequency Hopping RFID Reader”, by inventor C. L. Carrender.

The RF tags offer significant features at the sensors. The tags includemicroprocessors. In the illustrated embodiments, the microprocessorsallow for calibration, compensation, preprocessing, and onboarddiagnostics and prognostics. Each tag includes a large amount ofnonvolatile memory. In some embodiments, the RFID tags are used as dataloggers. The tags use the memory to periodically or at various timesstore data that is measured by the sensors. The nonvolatile memory isalso used to store setup information that is particular to the type ofsensor and the tag application requirements. For example, the timeperiod for acquiring data is user settable (e.g., times when data is tobe taken and frequency of data logging within specified time ranges).Each control tag and RFID tag included in the assemblies 31-37 has itsown unique identification code or ID which is a main element in the RFprotocol for communications. In some embodiments, the RF link betweenthe reader 40 and the control tag or RFID assembly 31-37 is two way (RFreader 40 request tag to transmit). In other embodiments, the RF linkbetween the reader 40 and the control tag or RFID assembly 31-37 is oneway (tag periodically transmits to an RF reader). In some embodiments,the reader 40 is coupled to (or selectively coupled to) the Internet anddefines a web server so that process reporting is performed via webpages and so that users can monitor process parameters using webbrowsers. Alternatively, data from the reader 40 is transferred at timesto a web server 46 separate from the reader.

The system of FIG. 1 can be adapted for use with either sliding stem orrotary stem control valves and actuator assemblies with either pneumaticor electromagnetic controllers.

Another RFID sensor assembly design is shown in FIG. 2A. The RFID sensorassemblies are relatively small. The RFID sensor assembly 50 that isshown in FIG. 2A is configured to sense temperature and impact(acceleration). Other parameters are sensed in alternative embodiments.The RFID sensor assembly 50 includes a processor 54 that can accommodateboth analog and digital sensors. In the illustrated embodiment, theprocessor 54 is a Texas Instruments 430×325 integrated circuitmicroprocessor. Other embodiments are possible. A thermocouple 53 and atemperature sensor 55 are coupled to the microprocessor. In theillustrated embodiment, the thermocouple 53 is a high temperaturethermocouple. Other temperature sensors are possible. The system 50further includes an impact sensor or accelerometer 57 coupled to theprocessor 50; e.g., via a buffer op-amp.

The assembly 50 further includes an RF transceiver 56 coupled to theprocessor 54 and to an antenna 58. The assembly 50 further includes alow power RF detector 60 configured to provide a wakeup signal to theprocessor 54.

The assembly 50 further includes a battery 62 coupled to the integratedcircuit 54 to supply power to various components of the assembly 50 thatrequire electrical power. In the illustrated embodiment, the assembly 50includes a power supervisor 64 coupled to a reset input of theintegrated circuit 54 and a power on/off switch 66 coupled between thepower supervisor 64 and the battery 62. The assembly 50 further includesa battery monitor 68 coupled to the integrated circuit 54 and configuredto monitor the condition of the battery. In the illustrated embodiment,the assembly 50 further includes a super capacitor or ultracapacitor 70and an LDO regulator 72 having an input coupled to a positive terminalof the ultracapacitor 70. The input of the LDO regulator 72 and thepositive terminal of the super capacitor 70 are also coupled to theon/off switch 66. The LDO regulator 72 has an output that provides aregulated voltage to the various electronic components of the assembly50. The ultracapacitor 70 provides supplemental power for RFcommunications and allows continued operation when the battery 62 isreplaced. The components of the assembly 50 other than the battery 62and thermocouple 53 are enclosed in a common housing 74 and the battery62 is enclosed in a housing 76 that is removable from the housing 74.The components enclosed in the housing 74 and in the housing 76, and thehousings 74 and 76 together can be referred to as an RFID tag 51.

In some embodiments, sensors such as strain gauges and/or LVDTs areused. In such embodiments, interface circuitry is provided between thesensor and the microprocessor 54.

The reader 52 (FIG. 2B) includes a transceiver 78 configured tocommunicate with the transceiver 56 (FIG. 2A). The reader 52 furtherincludes a processor 80 coupled to the transceiver 78. In theillustrated embodiment, the processor 80 is a Texas Instruments 430×325integrated circuit microprocessor. The reader 52 further includes abattery 82. The reader 52 further includes an LDO regulator 84configured to provide a regulated voltage to electrical components ofthe reader 52. The reader 52 further includes an on/off switch 86coupled between the battery 82 and the LDO regulator 84. The reader 52also includes an interrogate switch 88 which, when actuated, causes thereader 52 to interrogate the tag assembly 50 (FIG. 2A). The reader 52further includes input/output interfaces such a display 90.

In the illustrated embodiment, the reader 52 further includes a lowbattery indicator, a power on indicator 92, and a speaker 96. Otherembodiments are possible.

In the illustrated embodiment, the reader 52 is configured to be coupledto a PDA or portable computer. In alternative embodiments, the reader 52is coupled to or incorporated in a PDA or portable computer and uses thedisplay and/or speaker, and/or keyboard or input interface of the PDA orcomputer.

Some aspects of the invention provide a suite of RFID sensor assembliesfor sensor use in industrial process control. The suite can include, forexample, sensors configured to sense one or more of temperature,pressure, strain, or other process control parameters. In some aspectsof the invention, a tailored mechanical package or mounting structure isprovided to allow the RFID tag to be readily adapted to a particularprocess component or parameter.

For example, FIG. 3 is a perspective view of a sensor assembly 150,which can be substantially similar to the RF tag assembly 50 shown inFIG. 2A. The sensor assembly 50 includes an RFID tag 151, which can beidentical to or substantially identical to the RFID tag 51 shown in FIG.2A. The assembly 151 is configured to be used to measure temperature andmay be placed in a high temperature environment. The assembly 151includes a probe or waveguide 152 having first and second ends 153 and154. The first end 153 defines a tip, and a thermocouple 155 issupported on the tip. The RFID tag 151 is supported on the second end154.

An RFID sensor assembly for use with a fluid conduit such as one used ina nuclear reactor includes a band that encircles the fluid conduit 156,and an RFID tag supported by the band. The sensor assembly can be forsensing temperature, such as the sensor assembly 150 shown in FIG. 3.The RFID sensor assembly 150 is for use with a fluid conduit 156 andincludes a band 157 that encircles the fluid conduit 156, and an RFIDtag 151 supported by the band 157.

An RFID sensor assembly 200 for use in sensing pressure is shown in FIG.4 and includes a gas inlet port 202 configured to be coupled to a porton a conduit 206. For example, the gas inlet port, in some embodiments,is configured to be coupled (mechanically mated) to an ancillary port orthreaded stub on a flow pipe.

A variety of additional RFID sensor assembly designs is contemplated,the above specific designs being provided by way of example. Each RFIDsensor assembly includes a mating adaptor that allows for ease ofinstallation and minimization of modification to existing processcontrol components. Some RFID sensor assemblies just sense switchclosures such as for limit switches or relay contacts.

The ability to locally add desired sensing to an industrial processprovides tremendous flexibility for continually adding to, modifying, orenhancing a sensor network.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A system comprising: a valve; a plurality of RFID sensor assembliescoupled to the valve to monitor a plurality of parameters associatedwith the valve; a control tag configured to wirelessly communicate withthe respective tags that are coupled to the valve, the control tag beingfurther configured to communicate with an RF reader; and an RF readerconfigured to selectively communicate with the control tag, the readerincluding an RF receiver:
 2. A system in accordance with claim 1 whereinthe valve is a fluid-operated valve.
 3. A system in accordance withclaim 2 wherein the valve includes a valve positioner, an electricalconductor, and an I/P transducer coupled to the valve positioner by theelectrical conductor, and wherein at least one of the plurality of RFIDsensor assemblies is coupled to the electrical conductor.
 4. A system inaccordance with claim 2 wherein the valve includes a pneumatic actuator,a valve stem coupled to the pneumatic actuator, and an actuator-valvestem coupler, and wherein at least one of the plurality of RFID sensorassemblies is coupled to the actuator-valve stem coupler.
 5. A system inaccordance with claim 2 wherein the valve includes a pneumatic actuator,a valve positioner, and a fluid conduit in fluid communication betweenthe pneumatic actuator and the valve positioner, and wherein at leastone of the plurality of RFID sensor assemblies is coupled to the fluidconduit between the pneumatic actuator and the valve positioner.
 6. Asystem in accordance with claim 2 wherein the valve includes a pneumaticactuator, a valve positioner, a booster, a first fluid conduit in fluidcommunication between the pneumatic actuator and the booster, a secondfluid conduit in fluid communication between the booster and the valvepositioner, and wherein at least one of the plurality of RFID sensorassemblies is coupled to the first fluid conduit and at least anotherone of the plurality of RFID sensor assemblies is coupled to the secondfluild conduit.
 7. A system in accordance with claim 6 and furthercomprising a fluid supply line in fluid communication with the booster,and wherein at least one of the plurality of RFID sensor assemblies iscoupled to the fluid supply line.
 8. A system in accordance with claim 7and further comprising a regulator valve in fluid communication betweenthe fluid supply line and the valve positioner, a conduit between theregulator valve and the valve positioner, and wherein at least one ofthe plurality of RFID sensor assemblies is coupled to the conduitbetween the regulator valve and the valve positioner.
 9. A system inaccordance with claim 1 and further comprising a conduit upstream of thevalve and a conduit downstream of the valve, wherein at least one of theplurality of RFID sensor assemblies is coupled to the conduit upstreamof the valve and at least another one of the plurality of the RFIDassemblies is coupled to the conduit downstream of the valve.
 10. Asystem in accordance with claim 1 wherein the valve includes a seat andwherein the RFID sensor assemblies are used to determine valve seatingforce.
 11. A system in accordance with claim 1 wherein the valveincludes a spring and wherein the RFID sensor assemblies are used todetermine a spring preload of the spring.
 12. A system in accordancewith claim 1 wherein the valve includes a spring and wherein the RFIDsensor assemblies are used to determine a spring constant of the spring.13. A system in accordance with claim 1 wherein the valve includes aspring and wherein the RFID sensor assemblies are used to determinespring compression.
 14. A system in accordance with claim 1 wherein theRFID sensor assemblies are used to determine a friction load on thevalve.
 15. A system in accordance with claim 1 wherein the RFID sensorassemblies are used to determine valve position.
 16. A system inaccordance with claim 1 wherein the RFID sensor assemblies are used todetermine valve stroke times.
 17. A sensor assembly comprising: an RFIDtag; a thermocouple; and a probe having first and second ends, the firstend defining a tip, the thermocouple being supported on the tip, and theRFID tag being supported on the second end and electrically coupled tothe thermocouple.
 18. A sensor assembly in accordance with claim 17wherein the probe defines an electrical conductor electrically couplingthe RFID tag to the thermocouple.
 19. A sensor assembly in accordancewith claim 17 wherein the RFID tag includes memory and is configured tolog measurements from the thermocouple, at different times, in thememory.
 20. A plurality of RFID sensor assemblies for sensor use inindustrial process control, the plurality comprising: sensors configuredto sense at least two of temperature, pressure, and strain; at least oneof the sensor assemblies including a band configured to encircle a fluidconduit; and an RFID tag supported by the band and in electricalcommunication with at least one of the sensors.
 21. A sensor assembly inaccordance with claim 20 wherein the RFID tag includes memory and isconfigured to log data in the memory from the at least one sensor inelectrical communication with the RFID tag, at different times.
 22. Asensor assembly comprising: an RFID tag; a pressure sensor; and a bandconfigured to encircle a fluid conduit, the RFID tag being supported bythe band and in electrical communication with the pressure sensor.
 23. Asensor assembly in accordance with claim 22 wherein the RFID tagincludes memory and is configured to log data from the pressure sensorin the memory at different times.
 24. A method of monitoring anindustrial process which makes use of a valve, the method comprising:coupling a plurality of RFID sensor assemblies to the valve to monitor aplurality of parameters associated with the valve; providing a controltag to wirelessly communicate with the respective tags that are coupledto the valve, the control tag being configured to communicate with an RFreader; and selectively communicating with the control tag using an RFreader, the reader including an RF receiver.
 25. A method in accordancewith claim 24 wherein the valve is a fluid-operated valve, wherein thevalve includes a valve positioner, an electrical conductor, and an I/Ptransducer coupled to the valve positioner by the electrical conductor,and wherein the method comprises coupling at least one of the pluralityof RFID sensor assemblies to the electrical conductor.
 26. A method inaccordance with claim 24 wherein the valve is a fluid-operated valve,wherein the valve includes a pneumatic actuator, a valve stem coupled tothe pneumatic actuator, and an actuator-valve stem coupler, and whereinthe method comprises coupling at least one of the plurality of RFIDsensor assemblies to the actuator-valve stem coupler.
 27. A method inaccordance with claim 24 wherein the valve is a fluid-operated valve,wherein the valve includes a pneumatic actuator, a valve positioner, anda fluid conduit in fluid communication between the pneumatic actuatorand the valve positioner, and wherein the method comprises coupling atleast one of the plurality of RFID sensor assemblies to the fluidconduit between the pneumatic actuator and the valve positioner.
 28. Amethod in accordance with claim 24 wherein the valve is a fluid-operatedvalve, wherein the valve includes a pneumatic actuator, a valvepositioner, a booster, a first fluid conduit in fluid communicationbetween the pneumatic actuator and the booster, a second fluid conduitin fluid communication between the booster and the valve positioner, andwherein the method comprises coupling at least one of the plurality ofRFID sensor assemblies to the first fluid conduit and coupling at leastanother one of the plurality of RFID sensor assemblies to the secondfluild conduit.
 29. A method in accordance with claim 28 wherein a fluidsupply line is in fluid communication with the booster, and wherein atleast one of the plurality of RFID sensor assemblies is coupled to thefluid supply line.
 30. A method in accordance with claim 29 wherein aregulator valve is in fluid communication between the fluid supply lineand the valve positioner, a conduit is between the regulator valve andthe valve positioner, and wherein at least one of the plurality of RFIDsensor assemblies is coupled to the conduit between the regulator valveand the valve positioner.
 31. A method in accordance with claim 24wherein a conduit is upstream of the valve and a conduit is downstreamof the valve, wherein at least one of the plurality of RFID sensorassemblies is coupled to the conduit upstream of the valve and at leastanother one of the plurality of the RFID assemblies is coupled to theconduit downstream of the valve.
 32. A method in accordance with claim24 wherein the valve includes a seat and wherein the method comprisesusing the RFID sensor assemblies to determine valve seating force.
 33. Amethod in accordance with claim 24 wherein the valve includes a springand wherein the method comprises using the RFID sensor assemblies todetermine a spring preload of the spring.
 34. A method in accordancewith claim 24 wherein the valve includes a spring and wherein the methodcomprises using the RFID sensor assemblies to determine a springconstant of the spring.
 35. A method in accordance with claim 24 whereinthe valve includes a spring and wherein the method comprises using theRFID sensor assemblies to determine spring compression.
 36. A method inaccordance with claim 24 and comprising using the RFID sensor assembliesto determine a friction load on the valve.
 37. A method in accordancewith claim 24 and comprising using the RFID sensor assemblies todetermine valve position.
 38. A method in accordance with claim 24 andcomprising using the RFID sensor assemblies to determine valve stroketimes.
 39. A method of manufacturing a sensor assembly, the methodcomprising: providing an RFID tag; providing a thermocouple; providing aprobe having first and second ends, the first end defining a tip;supporting the thermocouple on the tip, and supporting the RFID tag onthe second end and electrically coupling the RFID tag to thethermocouple.
 40. A method in accordance with claim 39 and comprisingusing the probe to define an electrical conductor electrically couplingthe RFID tag to the thermocouple.
 41. A method in accordance with claim39 wherein the RFID tag includes memory, the method comprising loggingmeasurements from the thermocouple, at different times, in the memory.42. A method of using a plurality of RFID sensor assemblies for sensoruse in industrial process control, the method comprising: providing aplurality of sensors configured to sense at least two of temperature,pressure, and strain; providing a mechanical package to support at leastone of the sensors and define a sensor assembly, the package including aband configured to encircle a fluid conduit; and supporting an RFID tagby the band, in electrical communication with at least one of thesensors.
 43. A method in accordance with claim 42 wherein the RFID tagincludes memory, the method comprising configuring the RFID tagsupported by the band to log data, at different times, in the memoryfrom the at least one sensor supported by the band.
 44. A sensor methodcomprising: providing an RFID tag; providing a pressure sensor;providing a band configured to encircle a fluid conduit; supporting theRFID tag by the band and placing the RFID tag in electricalcommunication with the pressure sensor.
 45. A method in accordance withclaim 44 wherein the RFID tag includes memory and is configured to logdata from the pressure sensor in the memory at different times.